In prior art, as shown in FIGS. 29 and 30, the force of the piston 1, which is reciprocably moved in the cylinder 11 of a cylinder head 10, is transferred to a crank-pin 7 through a piston-pin 9 and a connecting rod 8, so that a crank shaft 2 is rotated by the transferred force.
A connecting rod cap 6, which facilitates such a basic movement, has a function for encompassing the crank pin 7, and a connecting rod cap bolt 5 fixedly clamps the connecting rod 8 and the connecting rod cap 6. Further, a counterweight 3 is dynamically acted on by inertia, and by a crank shaft web 4 the connecting rod 8 is prevented from axial movement on the crank pin 7.
In such structures, the connecting rod 8 has gaps 15 in the connecting part coupled to the piston 1 and the piston pin 9, so that any relative position error between the cylinder block and the crank shaft 2 is compensated. Such a function has a compensation by slipping, and bending for the connecting rod is always induced. Accordingly, noises are produced and fuels are spent wastefully. In addition, the gaps 15 are possibly compensated only relative to the position error for a direction parallel with only the crank shaft 8, and as to a position error for the other direction the compensation is not made.
In accordance with such structures, when the piston 1, the connecting rod 8 and the crank shaft 2 are completely assembled, in case relative positions and relative angles on the above three components 1, 2, and 8 are not exactly aligned, severe frictions take place on the mutual connection parts, and great noises and severe vibrations occur. Accordingly, there have been drawbacks in that the fuels are spent wastefully and the apparatuses are rapidly worn away.
Thus, when the engine is practically manufactured, in order to compensate the error occurring in all directions of a solid angle 360.degree. (4.pi..omega. angle), the piston diameter is always formed smaller than the cylinder diameter, and it is used without any changes, maintaining the great gaps.
As described above, in order to reduce leakage of the fuels in the broad gap between the cylinder and the piston and to inhibit introduction of the engine oil into the combustion chamber, various piston rings have been used.
Although these piston rings has reduced leakage of fuels and penetration into the combustion chamber of the engine oil, the mutually turbulent strikes, which take place owing to the broad gaps between the piston and the cylinder, are not able to be removed, and they result in an unnecessary excess of vibration and noise in the engines, abnormal abrasion in the parts, wastes of fuels, pollution, etc.
Further, allowable error limit through the working procedures of the crank shaft is ultimately not able to be minimized, owing to making the connecting rod as a rigid body, and manufacture for the crank shaft is difficult.
Accordingly, the crank shaft machining apparatuses are abnormally expensive, and problems which have reduced production yields have taken place.
In addition, in the internal combustion engines with reciprocating movement which have been used the piston generally, and in the reciprocating movement pumps which have used the piston, the piston 1 has a solid, rigid body. In order to prevent fixation during insertion into the cylinder 11 of the piston, due to the thermal expansion and construction, the outer diameter of the piston 1 has been manufactured smaller than the inner diameter of the cylinder 11.
Accordingly, very broad gaps have been formed between the piston 1 and the cylinder 11.
As described above, such conventional structures have broad gaps formed at random between the cylinder 11 and the piston 1. In case these gaps are not filled up by the proper methods, the compressible fuels or gases all leak away through the gaps, and original functions for the cylinder 11 and the piston 1 could not be realized.
Thus, in order to prevent leakage in excess and to increase efficiency, in the compressible fuels and gases, deep and narrow grooves on the upper periphery of the piston, the so-called "crown", are machined through all the circumference.
As a result of machining grooves in the circumference, piston rings are inserted into the grooves and prevent leakage of the gases from the gaps between the cylinder 11 and the piston 1.
Therefore, the practical structures of the piston 1, constructed as described above, and the pistons 1 which have been used throughout the world at the present time, never carry out the practical piston functions, that is, fluid compressible functions, and conduct only the piston ring transporting action.
Further, a low part of the piston, the so-called "skirt part", has an object in maintaining contact at the right angle between the cylinder 11 and the piston ring. However, as described above, owing to the broad gap or clearance between the cylinder and the piston, when the piston is moved up and down the piston orientation is changed and causes the phenomenon of moving slantwise left and right, the so-called "tilt", and the phenomenon of so-called "slap" in which the cylinder is struck by the piston. The tilt phenomenon and the slap phenomenon produce three bad influences on the engine as follows:
a) Whenever the piston motion is changed in the progressive directions up and down, noises take place one time owing to the impact of the slap strike. PA1 b) Whenever the piston motion is changed in the progressive directions up and down, pivot functions of the piston rocking movement are carried out in the state to fit the piston ring in the groove at the moment the tilt motion takes place, and at the same time the cylinder wall and the contact angle of the piston ring are recontrolled. At the same time, the piston tilt motion has no mono-centric rocking, and has poly-centric rocking. Accordingly, although there are short moments, an original position returning phenomenon takes place, twisting all the piston rings. At this time, a phenomenon of rotating in any direction takes place, sliding within the groove in the piston ring. PA1 c) The piston ring carries out sliding movement in the groove slowly at any directions, changing continuously the contact angle between the piston ring and the cylinder wall through the tilt motion. Accordingly, the corner angle of the piston ring which is required for the piston ring becomes blunt slowly along all the circumference of the piston ring, and at the moment the piston ring returns to the original position, maximum pressure on the top dead center is distributed. As a result of the distribution for the pressure, leakage amount of the compressible gases has a maximum value. As described above, in the influences on the engine, the tilt phenomenon and the slap phenomenon in the piston produce vibration, noises and fuel losses when the engine is rotated at a high speed.
Such great energy-consuming combined phenomena have a very small input and take place only at the top dead center and the bottom dead center positions, depending upon only the inertia of the inertia rotation. Accordingly, they produce greatly bad influences on the homogeneous output of the engine.